I'm printing on Ilford multigrade fiber-based matte paper, but they're wrinkled even after I flatten them. After I take them out of the orbit wash, I firmly squeegee both sides and put them on the drying rack for ~6 hours then flatten them for 4 minutes at 180 degrees F in a hot press and 4 minutes under cool weight.
Most of the curve is gone, but some of my prints are wrinkly near the edges. I've tried flattening longer with no success. Am I squeegeeing too soft or too hard? It didn't happen before but now it's happening to most of my photos and I can't think of anything that I've changed in my darkroom process.
Tried searching on here before I posted, but all I could find were tips for flattening them when they're just curved a little, but this is beyond that.